Franklin Delano Blenkinsop
Franklin - His first name, forename, or given name. This would once have been his Christian name or baptismal name, but these terms have gone out of fashion in these multi-cultural times.
Delano - His middle name.
Blenkinsop - His surname, family name or last name.
The answer to a question about your name depends on who is asking the question, for example:
When he is making a table reservation: Blenkinsop
When booking an airline ticket: Blenkinsop - Franklin Blenkinsop, or Franklin Blenkinsop
When meeting new colleagues: Franklin Blenkinsop or Franklin
At the gym: Franklin or, perhaps, Frank/Frankie.
However, these are only general ideas. People say different things.